1Preheat oven to 400 degrees F. Grease mini loaf pans or line muffin tin with paper liners.
2In a large bowl, combine flour, flax, brown sugar,baking powder and salt.
3In a separate bowl, whisk together milk, melted butter, syrup, sour cream, egg and vanilla. Stir into dry ingredients just until moistened. Fill prepared loaf pans or muffin cups two-thirds full.
4In a small bowl, combine topping ingredients and cut in butter until crumbly. Sprinkle over tops of muffin batter.
5Bake for muffins 16-20 minutes or until muffin tests done.
Mini loafs bake for 30-35 minutes or until toothpick comes out clean.
Cool completely on wire rack before dusting lightly with powdered sugar.